runtime: DateTimeOffset does not parse a valid ISO-8601 datetime string

Description

DateTimeOffset does not correctly parse a valid ISO-8601 datetime string. Wikipedia claims the current ISO-8601 definition prefers a comma as the decimal mark for the lowest time order present:

However, DateTimeOffset is not capable of parsing a datetime string with a comma decimal mark for the lowest time order when that time order is seconds:

        static void Main(string[] args)
        {
            static void Test()
            {
                var dateString = "2021-04-23T13:04:17,307642270+02:00";

                DateTimeOffset date = DateTimeOffset.MinValue;

                try
                {
                    date = DateTimeOffset.Parse(dateString);
                }
                catch (Exception e)
                {
                    Console.WriteLine($"date: {e.Message}");
                }
                finally
                {
                    Console.WriteLine($"date: {date}");
                }
            }

            Test();
        }

Configuration

Code above running on .NET 5.0.202 on Windows 20H2 (OS Build 19042.928).